Typically, a video processing solution is composed of hardware accelerators (HWAs), connected to a central programmable unit (CPU) that is in charge of initializing and starting the different hardware accelerators along with managing all their input/output data transfers. As the image resolutions to be processed become higher and video standards become more complex, the number of hardware accelerators needed to support such features may increase. Thus the task scheduling on the different HWAs may become a bottleneck that requires increased processing capabilities in the CPU. Increasing performance of the CPU may be detrimental to size and power usage.
In a typical implementation, all nodes are activated and controlled by the central CPU. Data can be exchanged between nodes and the CPU either by a common memory or by DMA (direct memory access). The CPU typically responds to interrupt requests from the various HWAs to schedule tasks.
The vertical blanking interval (VBI), also known as the vertical interval or VBLANK, is the time difference between the last line of one frame or field of a raster display, and the beginning of the first line of the next frame. It is present in analog television, VGA (video graphics array), DVI (digital visual interface) and other signals. During the VBI the incoming data stream is not displayed on the screen. In raster cathode ray tube displays the beam is blanked to avoid displaying the retrace line; see raster scan for details.
The VBI was originally needed because of the inductive inertia of the magnetic coils which deflect the electron beam vertically in a CRT; the magnetic field, and hence the position being drawn, cannot change instantly. For horizontal deflection, there is also a pause between successive lines, to allow the beam to return from right to left, called the horizontal retrace or horizontal blanking interval. While modern digital equipment does not require a long blanking time, it must be designed to retain compatibility with the broadcast standards intended for older equipment.
Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.